Ship structure



1945 E. F. MoRoNEY 1 2,382,499

SHIP STRUCTUBE Filed Feb. 17, 1942 6 Sheets-Sheet 1 1945- E. F. MORONEY2,382,499

SHIP STRUCTURE Filed Feb. 17, 19 42 6 Sheets-Sheet 2 60 INVE NTore:Edward fizflera d Momma BM 1 J5 ATTY.

Aug. 14, 1945. E. F. MCRONEY SHIP STRUCTURE 6 SheetSPSheet 4 Filed Feb.17, 1942 \N VE'NT A'Z, Edward Fl-hsermd Moronea Aug- 14, 4 E. F. MORONEYSHIP STRUCTURE 6 Sheets-Sheet 6 Filed Feb. 17, 1942 Patented Aug. 14,1945 SIHP STRUCTURE Edward Fitzgerald Moroney, Penarth, Glamorgan,

South Wales Application February 17,

In Great Britain J 4 Claims.

This invention relates to improved design and methods of construction ofvessels of various descriptions-for example warships, merchant ships,yachts and floating docks-storage tanks and other structures, wherebygreat advantage is obtained by down hand welding in electric and otherwelding processes, including automatic machine welding.

An object of the invention is to obtain lightness with stiffness in thestructure and economy by making use of plate material without extraneousstiffening.

Another object of the invention is to make provision whereby most partsof the structure can be fabricated or built independently of each otherand whereby for final assembly only a minimum amount of welding isrequired on the site to complete the structure. By virtue of suchprovision, in the case of ships the launching ways are not long occupiedfor any single ship, thereby afiording facilities for rapid andeconomical construction. Moreover, a considerable amount of constructioncan be done under cover.

Another object of the invention is to make provision whereby variousparts can be welded together On a construction table, or jig, which canbe set to any angle so that down hand welding can be effected, either byhand or machine process. Upon this table the various pieces can beaccurately spaced and secured for welding. Brackets, frames, floors, andgirders may be made from narrow thin plates, which are cut intogeometrical shapes as required, and parted by gas flame oro'xy-acetylene burner. Such plates may be formed in. a machine withbossings or indentations which give great stiffness to them.

Such plates placed at any required distance apart may be joined byembossed or otherwise stiiiened joining pieces which are welded inplace, thus forming webs. These plates and joining pieces may be formedto provide lightening holes in the region of the neutral axis of thewebs, where material can best be spared.

Another object of the invention is to eliminate the use of rolledsectional material-that is, material of angle-section, bulb-section,I-section, T-section, channel-section and so on-and nevertheless obtainthe necessary stiffness and strength in the material itself by bossingand flanging where required.

Accordingly, the invention resides in a ship or other structure composedof plate units arranged in superposed strakes, each unit comprising amain plate and stiffening members formed of narrow mutually transverseplates in 1942, Serial No. 431,225

anuary 28, 1941 planes perpendicular to the plane of the main plate,said units being welded together along the abutting edges of adjoiningmain plates and along butt ends of said stiffening members.

The invention also resides in a. ship or other structure composed ofplate units arranged in superposed strakes, each unit comprising a mainplate, a stringer formed of a narrow flanged plate welded edgewise tothemain plate and extending alongside one longitudinal edge thereof and aseries of frames formed as narrow flanged plates welded edgewise to themain plate and extending transversely from said stringer to the oppositelongitudinal edge of the main plate, said units being welded togetheralong the abutting edges of adjoining main plates and along the buttends of aligned stringers and along butt ends of the frames.

In an alternative construction, the narrow flanged plate forming thestringer is an integral part of the main plate and is not welded theretobut is formed by flanging the main plate along a longitudinal edgethereof.

The invention will now be described by way of example as applied to theconstruction of a ship with reference to the accompanying drawings, inwhich- Fig. 1 is a mid-section of one side of the hull of a shipconstructed according to the invention.

Fig. 1a is a section on the line Ia of Fig. 1 and Fig. 1b is afragmentary view to a larger scale of the vertical weld between adjacentmain plates of the same strake.

Figs. 2, 3 and 4 are fragmentary midship-sections respectively showingmodified deck structures.

Fig. 5 shows a beam unit which is a component of the deck structureaccording to Fig. 4.

Fig. 6 is a. fragmentary midship-section showing a modified bottomstructure; and Fig. 7 shows a girder component of the bottom structureaccording to Fig. 6.

Fig. 8 shows a plate unit which is a component of the ship sidestructure.

Fig. 9 shows a beam unit, being a modification of that shown by Fig. 5;and Fig. 10 is a section On line X of Fig. 9;

Fig. 11 is a fragmentary elevation of a girder unit somewhat similar toa unit in the bottom structure according, to Fig. 6; and Fig. 12 is asection on line XII of Fig. 11.

Figs. 13 and 14 illustrate alternatives of a preliminary stage in theformation of deep-web girder beam and frame units.

15 to 20 are sections to a large scale showing various modifications ofthe interstrake joints shown in Fig. 1.

Fig. 21 is a fragmentary elevation and Fig. 22 a plan of the ships stem;and Fig. 23 is a section on line XIHII of Fig. 22.

Fig. 24 is a. section and Fig. 25 a fragmentary elevation of a bulkhead.

Fig. 26 is a plan ofapparatusfor cutti g plating to any required form,and Fig. 27 is a section on line XXVII of Fig. 26.

Fig. 28 illustrates the formation of strake unit.

Figs. 29 and 30 are a side elevation and an endelevation, respectively,of apparatus for; facilitating the welding of joints in thepreconstruction of the plate units.

Fig. 31 shows a valve chest welded to a. bilgetank top plate.

In the several figures, similar and corresponding parts are denoted bythe same reference characters.

Referring firstly to Fig. 1-, the ships side is composed of plateunitsall similar to one an other and arranged in superposed strakes eachconsisting of said'plate units welded end-'to-end, the units belongingto each intermediate strake being welded tothe units above and belowthem belonging. to the adjacent, upper and lower strakes. Each of thesevarious units consists of a. main plate 40, which is of, uniform'thickness andv is a side plate of. the shipfs hull; a stringer 4|, and.a series of, frames.42. One or these units} isshown in Fig. 8. As shown,the main plate. 40; is curved in accordance with its position inthehull. Thestringer 4| is a. narrow plate formed withanintegraldownturned'flange 43 and curved to fit against the inain plate, towhichit is welded edgewise along a line close. to the plates upperlongitudinal edge The stringer 4|; endsat the ends 01f the main plate.The frames .42 1 each consist; also-ofanarrow plate with an integralflange 44 and each of them is welded. edee ise othe a ate wa t itend; tse romi h s in r-to t e lower e o the main plate. The frames 42. eachend; at. or. slightly below said lower edge (seealsoF-igs. L to. 0 he wded. d f a hfl the ames flriscut; t th urvature. of. the res ct ve-ma n.

plate. Thus it willbe clear, that the stiffening members constituted bythe stringer 4,11 and: frames 42: all endatv or about. the limits ofthev main plate 40.

All the platev units which form thesides of. the hull", and; ofwhichtheunit according to Fig. 8 is a typical example, are separatelypreconstructedall inreadinessfor butt-welding toone another at the placewhere theshipis being built. In Fig. 1, the uppermost strake of theseunits is denoted A, thelowermost strake is. denoted B; andtheintermediate strakes are denoted C. The. plate units of the strakes Care eachwelded-along the upper andlowerlongitudinaledges of their mainplates to the adjoining upper and lower main plates; and the lower endsof-the frames of' strakes A and C abut against and-arewelded' to thestringer 4| of the next lower strake. The abutting vertical-edges of Iadjacent main plates ineach strakeare welded to one another at 40a(Figs. la and 1b) andthe abutting ends of aligned stringers 4| arewelded .to-one another at 4| a. All of these weldingfoperat-ions may beperformed by down-hand -weldlng operations.

a bilge lower edges and of forming said edges and the edges of thestringers 4| in order that suitable spaces for the reception of weldingmaterial are provided. From the foregoing description it will beunderstood that the welding 45 between the main plates is applied in thebuilding of the ship, whereas the welding 46 between the stringers andthe main plates. is applied during-the preconstructed; elsewhere of theplateunits. It will be noted that in each modification, the space whichreceives the welding 45 opens upwards, so that down-hand welding is themethod employed. Likewise, an upwardly opening space for an auxiliary.run of back welding 45a between the r stringer 4| and the next uppermain plate 40 is also provided, except in Fig. 16 arrangement.

I m- Figs. and 16, the upper plate is bent or joggled inwards at b andthe upper edge is bevelled at 4110.

The Fig. 16 modification differs from the others in that the frames 42do not stop at the level of the main plate's lower edge but extend lowerbeyond said edge. Provision is thus made for an independent, auxiliaryrun of welding 460, between the main plates 40 at the back thereof. InFig. 17, both plates are joggled'and both edges are bevelled: In Fig.18, the desired space is got simply by appropriate bevelling of theadjoining edges, this modification being especially suitable for thickplates. In Fig. 19, the lower plate is joggled outwards at its upperedge and the lower edge of the upper plate is simply bevelled. Themodification according to Fig. 20 diil'ers from all the others in thatthe narrow flanged plate 4.|b is not welded to the main plate but is anintegral part thereof formed by bending or flanging the upper portionthereof inwards at Me to give the web portion Mo and downwards, at. themargin togive the flange 43 as in the other modifications. The loweredge of the upper. plate is joggledsomewhat similarly. to themodification according to Fig. 17, butv said edge is welded. at 4.5,tothe bend Me. An embodiment such as shown by Fig. 20 is suitable mainlyfor thin plates. To facilitate thewelding. operations both in theconstruction. of the plate unitsand in thebuilding, of the ship., theframesthe inner topand bottom corners of 42. are cut awayat.

In each embodiment, the framesflofthe upper' unit, rest upon thestringer 4| of the lower unit, andin this way the adjacent longitudinaledges or surfaces of the upper and lower plates 40, are maintained inthe-pr oper relationshi for welding. Moreover, said ed es'or surfacesare complemental in the sense that they cooperate to provide, threquisit u ly opening space fo downhand weldin Moreover, as the run ofback,

weldinga on46 extends above. the stringer? 4| of, the lower-'unit,saidstringer leavesthe way. clear for, downhand welding.-

The plates ofuppenand lower units. are co.-

planar, each being flatexcepuwhere it maylcurve;

to suit the contourof the ship's hulL'and so the upwardly. opening spacebetween the. adjoining longitudinal :edges extends horizontally.- in.along substantially straight run.

Figs. 15 to 20 show-difierent-ways for forming At thestem and st'rni oi:the ship, weldedplate units may be provided instead of the:usual forged:

stem and stem posts. Asshownin-Figs. 21 b023, whichshows aportion-ofthestemof the-ship, the main'plates of-the-foremostplate-units (Fig.

8-) converge towards the stem. The latter com prises-verticallyextending stem plates 48 which. are curved'in horizontal section(Fig.22) so that they abut against one another in the centrallongitudinal plane of the ship and against the foremost main plates 40.The abutting edges are bevelled to provide spaces for the welding 49.The stem plates 48 are strengthened by webs or diaphragm plates 50 atthe level of the stringers 4|. These webs 50 are horizontal plates whichare welded at 5| along their eripheries to the stem plates and whichalso are welded to the stringers, These stringers and webs impart suchstrength to the hull of the ship that the welded plate structuredescribed serves adequately the function of the usual stem post, beingadapted to resist shock due to striking floating objects.

The stern post may be similarly constructed, but would be fitted with aforged or cast steel tube, having its axis longitudinally arranged, suchtube being Welded in position and being machined to receive the usualpropellershaft.

The ships various bulkheads are constructed in substantially the sameway as the ships sides.

- As shown in Figs. 24 and 25, a bulkhead is composed of preconstructedplate units arranged in superposed strakes. Each unit comprises a mainplate 52; a stringer which has a strengthening flange 54 and is weldededgewise to the main plate, alongside the upper edge whereof thestringer extends; and vertical frames 55 formed as narrow plates'whichhave strengthening flanges 56 and are welded edgewise to the main plate,the frames extending from the stringer to the lower edge of the mainplate. The units are welded together in the same way as described withreference to the building of the ships sides. There may be as few as twovertical frames per unit, but this number may be varied according to thestrength which the bulkhead must possess. Preferably, the webs 55 of theframes increase in width progressively from the top of the bulkhead tothe bottom to give the most advantageous strength-weight relationship.

Structural members such as beams, girders and frames, incorporated inthe ships structure may be preconstructed as deep-web units adapted forwelding a such into position in the building of the ship. For example,as shown in Fig. 1, deepweb beam units 51 are used to support the deck;deep-web girder units 58 are incorporated in the double-bottom tankstructure and deep-web frame units 59 are used at intervals incooperation with the frames 42 to impart transverse strength to the shipstrulcture. These units may all be made by substantially the samemethod, as will now be described.

Fig. 9 shows an example of a deep-web beam unit. The deep web consistsof two co-planar plates 60 which are interconnected at intervals byintermediate-plates BI and the lower portion of which is strengthened bya bottom flange 62. The intermediate-plates 6| are butt weldedtopand-bottom to projecting or salient edges of the web plates 60, theplates 6! being formed. to abut exactly against these edges. Between theintermediate-plates, large recesses 63 are formed in the web-plates inorder to leave open spaces and thus render the unit as light aspracticable along its neutral axis without detracting materially fromits strength. To increase the stiffness without adding to the weight,the web-plates 60 and the intermediate-plates 6| are impressed withindentations or corrugations 64 (Fig. which are formed (Fig. 9) to suitthe shape of the plates 60, 6|. Thus, it will be seen, the unit isdesigned to have maximum strength with minimum weight. The aforesaidindentations 64 have the 53 formed of a narrow plate beneficial effectthat they reduce or prevent vibration and exfoliation of scale and rust,which is a cause of rapid wastage in fiat plates.

Figs. .11 and 12 show an example, of a deepweb girder unit. Parts of andformations in said unit corresponding to those of the unit according toFigs. 9 and .10 are denoted by the same reference numerals. The twoexamples differ not only in the geometrical form of the projectionsandrecesses but also in that the opposed Web-plates 6|) in Fig.-11 areparallel whereas in Fig. 9 they are'mutually inclined t form a unit ofprogressively increasing depth.

The deep web plates may be cut from a'single stripof plate in the mannerillustrated by Figs. 13 and 14. As shown in Fig. 13, a flat strip ofplating 60 is out along a line 65 for example by means of a gas-burningcutter. The half-plates thus produced each have a cut edge outliningtrapezoidal projections marked Ella. inv Fig. 13;. and between each twoprojections of a half-plate there is a recess whose edge is marked b in;

Fig. 13. In cutting the half-plates to lengthwise size and assemblingthem as a welded unit according to Fig. 11, the procedure is such thatthe projections of each half-plate come exactly opposite to those of theother, half-plate so that the intermediate-plates Bl-will fit betweenopposed projections. x

Fig. 14 corresponds to Fig. 13 except that the projections and recessesare cut semi-circularly after which the semi-circular portion of eachprojection is cut-off diametrally to leave a straight edge forbutt-welding to the intermediate-plates 61, as shown by Fig. 9 I

Referring again to Fig. 1 and also to Figs. 2 to 7 it will be seen thatvarious examples of deep-web units similar or substantially similar tothose described with reference to Figs. 9 to 1.4 are shown embodied inthe deck side and tankbottom structures of a ships hull.

Fig. 2 shows a deck structure 5'! comprising a number of preconstructeddeep-web units practically the same as shown in Fig. 9, the indentations64 not being drawn in Fig. 2 for clearness of illustration. The mutuallyinclined relationship between the upper and lower wed-plates gives aparticularly strong and useful construction for a structure of thisnature, which functions essentially as a cantilever. To add to thestrength of the hull, longitudinal stringers, in the form of flangedwebs 68, are welded between the abutting ends of the deep-web units.

The deck structures 510, according to Figs. 3

to 5 differ from the deck structures 51 in that their upper and lowerweb-plates 60 are not formed with projections and recesses but havestraight inner edges We to which'the intermediate plates 6| are welded.This gives a narrower deck beam unit well adapted for incorporation inthe ship structure in the same transverse planes as the narrower sideframes 42. The deeper beams 57 would beused only co-planar with deep-webside units 59 hereinafter described. These deeper beams not only addgenerally to the strength of the hull but are particularly useful forstrengthening the deck-structure beside hatch and other openings in thedeck. 7

In the deck structure 51 according to Fig. l, the deep-web units areformed in the manner according to Fig. 14, but the semi-circularprojections 60a are not completely cut off, being out along lines whichleave straight edges adapted to abut against one another as regardsseveral .of. the projections in any one unit, thus minimising the needfor additional; intermediate-plates II- Fig. 6 shows: a tank-bottomstructure compris.-: ing deep-web. units. practically the same. as inFig-11', Fig. '7 showing the upper pontionof the deep webaspreconstructed priorto. weldingto the lower portion with the distanceplates: be tween them.

Thetank-bottom. structure 58 according to Fig. 1 diifers from theforegoinglin. thatthe indentations. 6t curve along the bodyof the web.-plate 50 and surround each. recess 63 thereof;

In the side structure according tOFiga. 1), the deep-web units. 59 havetheir web-plates 60: cut substantially as. in Fig. 141, but the curvesare flatter and the projections are left in. their curved form, so thatthe mtermediate-plates Bl. must-alsobe curved: conversely to abut 'forwelding between opposed projections. This: procedure avoids. wastage of.material in making the webplates from the original. stripof: plate. Asaforesaid, these units. 59 are in. the same transverse planes. as. thedeep-web. deck beams 51 Although: the deep-web. units are of generalutility as deck-beams, for example in connection with. the usual:cambered deck 66 shown in Figs. 4. and: or with a flat deck (notshowmthey permit the construction of anovel formofdeck for cargo shipsnamely, a stepped deck-such as.il'- lustratedby. Figs. 1, 2. and. 3. Inthese figures, the stepped deck is denoted: by 61'. For use inconnection such. a deck, the deep-web units areespecially suitable, asthey may have upper and. lower web-plates. 60- which are mutuallyinclined with comparative steepness, thus giving a beneficial cantileverconstruction. In such a deck, .the'steps extend: longitudinally of theship and: go upirom; the sides of the shiptowardsthe centrallongitudinal: portion thereof; In addition, to. the structuraladvantages of such an arrangement, it. has certain advantages, namely:the. steps resist shocks. on. deck cargo; they afford. self-trimming forcargoes. such as coal and grain; they give extra. buoyancy; they affordample working space, giving. access foreand-'-aft atlevels higheranddrier than. flat or cambered decks: which tend to hold quantitiesofsea Water endangering the crew and: the ship.

-In a; deck structure-for flat or cambered decks (Figs.14. andS')thelongitudinal inter-unit stringers El; have deeper webs.

It be: seen that each, preconstructed plate unit of. the. deckstructure. consists of a deck plate 61., a series. ofi transverse.deep-web beams 5.1a, one or more deeper beams 51:, and alongitudinalstringer 68, allwelded together in. readiness forincorporation by welding in. the structure ofthe ship.- The lowerweb-plates 6.0; in both typesof beam 51 and 51a, are flanged alongtheir, bottom portion, at 69.. Ifhe top edges. of theupper web-plates60; are cut to. the curvature 01;? the decks, whether stepped. orcambered:

The double-bottom. tank structure also. consists; of: units which arepreconstructedin" readinose; for assembly in the shipstructure. Theseunits comprise twokinds. namely: (1). bottom plates 10. withlongitudinal keel or keelson plates welded thereto. (Figs. 1. and;6)';(2) top plates 12 with the upper portions; 6.0. of transverse deepwebgirders pre-welded thereto-(Fig. 7).

The bilge-tanks, (which. may. be. used; as. wing ballast tanks) arecomposed of completelmpreconstructed described. I

In the final assembly of the various plate plate units, as will behereinafter aasacae unitsat the site where the ship is.to be buflnthebottom plates 1.0 with longitudinal: keel: and keel.- son plates. 1.1:already welded .to them are. placed sid'e-by-side and end-to-endithroughout the extent" of the ships bottom and. they are. butt? welded:together from above. Then: the tank-top plates 12 withonly the upperportions. 60 on the deep-web girders. welded to them are lowereduponjacks 13 and set precisely in place in..rela.- tion. tothe plates12H. The lower portions 80. of the deep-web girders. with. the distanceplates 61: welded. to. them:- (these parts. have been previously.putinside the double-bottom. structure) are now set precisely-in placeand are spot-weldad (or tack welded) to the plates 10 and. 1.1. Theplates 12* and the attached upper portions. I (Fig. '1) are'temporarily.removed. to givefreedom to-complete the welding on the lower portions.II to the plates 10: and. 1|; 'I-he temporarily removed parts. arefinally replaced and welded permanently; The welding throughout is. doneby down-hand operations.

It will' be noted that needv for cement. is errtirely eliminated withconsequent. saving in weight.

With. reference now tolthe bilge tanks between the double-bottom tankstructure and the. sides (Figs. 1 aud t), these are; preconstructedi andin.- corporated in. the ships structure as follows. The bilge plates 14are-formedtothe appropriate curvature in: the usual: way. Then. bilgebracket plates-or diaphragm plates: 15: are welded tothe plates It so.as-tobe coplanar in the ship. structure with the side framesdl, island.the doublebottom. girders. Next the bilge-closing plates 16 are welded"in place, thus completing the general structune of: the bilge-tankunits. The units thus preconstructed. are taken. to the shipbuildingsite for. incorporation. by welding in. the shipsstructure. There theyare welded to the double-bottom tanks: and to one another endto-end.

. The plates. 1:5 in. general. are made as. open.- centre frames:(Se'Flg. 28), .but' where it is. desired that any of them: shallvseparate and seal one bilge tank. irom anotherthe plate 1.5. is in.-stead: left solid; for-example, in way of. the en.- gineroom. or othermachinery spaces. More.- over; the bilge plates. 13A of tanksv withsealed ends may be formed: with. openings (having. gratings) to thesea.v

Plates: 15. made as. open-centre frames may. be impressed with an]indentation. 11. around their open centres 18 (Figs. 1 and.6-) inordertostifien them. and prevent deterioration due; to exfoliation;

Corners. of. the doub1e.-bottom.tank.girder webs 60 and of the bilgediaphragm plates 15 may be cut away at 85. (except where said webs. andplates. seal. one. tank from. its neighbour), to expose; the adjacent:longitudinal welded. seams for examination. and to. permit. the: freepassage of water and air from space to.- space of. the. tanks and;bilges(see Figs. 1- and 6).

Valves or other fittingsto be mounted on the bilgetankscanreadilybe'welded implace during preconstruction. For example, Fig. 31' shows avalve with: a.- steel chest or body 19 set through ahole in; theclosing'plate16 of; a. bilge tank and welded-thereto. Such avalvewill.be practically shookproof.

With-reference to the side structures, the preconsuructed. unitsv (see.Fig.1 8)I are built-up strake by. strake anch welded. togetherend.-to-endz(Figs. la and: lb) andone-on topot another (Figs. 15

to20), as hereinbefore described. As shown by Figs. 1 and 6, thelowermostmain plates 48 and frames 42,59 are welded to the top edges ofthe bilge plates 14 and to the closing plates 16 in the same way asupper side-structure units (Fig. 8) are welded to lower side-structureunits.

Inthe building of the sides, the stringers 4| (or Mb) are particularlyuseful as platforms whereon to rest the upper units during assembly andwelding.

With reference to the deck structure, the preconstructed units (see forexample Fig.5) comprise a deck plate 66, a series of transverse deepwebbeam units 57a, with or without one or more deeper units 5?, and astringer web 68, these elements being all welded together. Thedeck unitsthus preconstructed are welded in position by firstly welding theoutermost of them to the corresponding side frames 42, with or without59, and to the tops of the side plates Ml, and then welding each of theinner deck units successively to the adjacent outer deck unit. Thislatter operation involves simply butt-welding the edges of the deckplates Bl to adjoining deck plates and welding the ends of the deep-webbeams to the stringers 68.

In Fig. 2, tubular scaffolding members are shown at 8| as means forsupportin the deck units while being welded in place. These members 8lhave adjustable screwed ferrules 85a, the level of which can beprecisely adjusted to ensure proper registration between the deck-plateedges to be welded together. The innermost deck unit shown being loweredinto place upon the ferrules Hid, while the intermediate unit is shownresting in position awaiting the outermost unit.

In the various preconstructed plate units hereinbefore described,certain of the plates must have an edge which is carefully shapedaccording to some predetermined curvature. For example, there are theedges of some of the side frame webs 42 (Fig. 8) and of some of the sideframe deep webs 60 to be welded to curved main plating 40; there are theuppermost edges of the deep-web deck beams tobe welded to cambered deckplates 61; there are also the lower edges of the deep-web deck beams ina simple cambered-deck arrangement such as illustrated by Fig. 4; andthere are also the edges of the stringers M (Fig. 8). To effect accuratecutting of the various plates the apparatus and procedure now to bedescribed with reference to the diagrammatic Figs. 26 and 2'7 may beadopted.

A line L similar to a given curve is drawn full size on a moulding loftor floor. An easily bent bar 82 of metal, for example lead or leadalloy, lightened by a series of holes 83, is bent to the precisecurvature of the line. Bending is affected by placing the bar on a board84 and using a carriage 85 to press the bar to the required curva ture.The carriage 85 is roughly triangular, there being two rollers 86 at twoof the angles and a tracer 81 at the third. The workmen move thecarriage along the bar meantime pressing upon it sufhciently to keep thetracer accurately on the line to be copied. The board 84 with the bar 82lying thereon set and inert is placed upon the plate to be cut and aburner is substituted for the tracer. The plate is thereafter cut toshape by moving the burner from end to end of the path set for thecarriage along the bar, the active edgecf which thus serves as atemplate.

The board 84 may form one of two boards hinged together like the coversof a book. When it is desired to cut a curve similar in shape but tovthe opposite-hand, the coverlike boards are closed with the bar heldbetween them and then they .are turned upside-down. Thereafter, the nowupper board is turned aside, leaving the bar exposed for further use asa template.

In the work of preconstructing the various plate units, a table 88 (Fig.28) may be used to support the plate, whether curved or fiat, to whichweb members (transverse and/or longitudinal) are to be welded. On thetable, the parts may be set in their precise co-relationship andspot-welded to one another to fix them in a preliminary manner. In Fig.28, a curved bilge plate 14 is shown on the table 88 and transversediaphragm plates I5 are positioned on the plate 14.

Thereafter, so that down hand welding may be employed throughout, aportable carrier 89, diagrammatically shown in Figs. 29 and 30 isutilised. The carrier 89 may be used beside a pit with a sloping wall 90permitting the carrier to be tilted at a steep inclination. The carriermoreover is tiltable sidewise to a steep inclination in eitherdirection. Thus, when the preliminarily fixed parts of a plate unit arepositioned upon the carrier, this can be tilted in some direction orother to expose each seam upwards for down-hand welding.

By virtue of the fact that almost the entire hull of the ship iscomposed of plate units preconstructed as hereinbefore described, thelength of time required to build a ship on a building slip isconsiderably reduced. Indeed, the usual shipyard slip is not essential,for the bottom portion of the ship could be built-up to the form of ashallow basin in a dry dock, then floated and removed to a wet dock orwharf under a simple jib crane or cranes of moderate size, and there theremainder of side units and the deck units could be added and welded inplace. Launching would thus be rendered unnecessary.

Although the invention has been described with reference to the drawingsas applied to ships the framing of which is a combination oftransversely and longitudinally constructed frames, it is alsoapplicable to ships of so-called longitudinal construction.

I claim:

1. A deck structure for use in ship construction composed of web-plateunits welded together endto-end to form deck beams, each of said unitscomprising web-plates and intermediate-plates which are welded to saidweb-plates to space them apart and which are themselves spacedlongitudinally apart to leave open spaces along the central axis of therespective deck beam, and deck plates secured across the tops of seriesof said units arranged sideby-side, each inner series of said unitsbeing arranged at a higher level than the next outer series so that thedeck plates form a deck structure of stepped formation with the stepsrunning longitudinally and rising in the direction from the ships sidesinwards.

2. A deck structure for use in ship construction composed ofside-by-side series of web-plate units welded together end-to-end toform deck beams, each of said units comprising inter-connectedweb-plates diverging outwards and the units of which each deck beamconsists being so arranged that their lower web-plates constitute asubstantially continuous member whereas their upper web-plates formsteps that rise from a low level at the ships sides to a high level atthe ships longitudinal central portion, and deck plates interconnectingthe deck-beams and covering them, said deck plates being'of steppedformation to suit the form of said upper web-plates.

3. In .a ship structure the 'sides 'of which :are built of sideplate-units arranged in superposed strakes, each of such unitscomprising a main plate, a stringer formed :of a narrow plate extendingalongthe main plate at one longitudinal edge thereof and terminatingsubstantially at the ends of said main plate and ,frames formed asnarrow plates extending transversely from said stringer terminatingsubstantially :at the opposite longitudinal edge of said main plate,:said units being welded together along abutting edgesof adjoining mainplates and at abutting :ends of aligned stringers and at said ends ofthe frames, the-combination of a structure constituting a ship's end.and'comprising vertically extending curved-plates which are butt-weldedto the main plates of the endmost of said side plate-units and which converge and abut at said end, and horizontal diaphragm plates which areperipl'ierally welded to said vertically extending plates and the endsof the stringers of said endmost units.

4. In a ship structure the sides of which are built of side plate-unitsarranged in superposed 'strakes, each of such units comprising a mainplate, astringer formed .of a narrow plate extending alongthe main plateat one longitudinal edge thereof and terminating substantially at theends of said main plate and frames formed as narrow plates extendingtransversely from said stringer and terminating substantially at theopposite longitudinal edge of said main plate, said units being weldedtogether along abutting edges of adjoining main plates and at abuttingends of aligned stringers and at said ends of the frames, thecombination of a structure constituting the deck of the ship andcomprising web-plate units welded together end-to-end to formdeck-beams, each of said units comprising web-plates and intermediateplates welded to said web-plates to hold them apart, the outermost ofsaid web-plate units in each of said deck-beams having its outer endwelded to the top of a corresponding one of said frames, and deck-plateswelded to the tops of saiddeck-beams and to the main plates of saidside-plate units.

EDWARD FITZGERALD MORONEY.

